Americas are angry with their politicians but nuanced in their political opinions. Voters in Alaska simultaneously ousted their Democratic Senator and legalized the use of marijuana. Floridians gave 505,000 more votes medical use of pot than they did in re-electing Republican Gov. Rick Scott.

Milton Friedman and William F. Buckley took their places on the pantheon of the Right while arguing against drug prohibition. The electorate appears to be moving their way.

Which makes sense. If you want to limit government and protect individual liberty, it’s impossible to ignore the ill consequences of arresting and imprisoning millions of people for using illicit substances. Drug use is bad. Arresting people for using drugs is worse.

But conservatives have another reason to abandon the drug war: federalism.

The Drug War has poisoned almost everything it touches. The rule of law suffers. Lawyers speak of the drug exception to the Fourth Amendment, since judges often sacrifice Fourth Amendment protections when drugs are involved. Police departments seize property—theft in all but name—allegedly tied to drugs without filing charges or even proving a connection. Cops admit to lying to justify arrests. Prosecutors acknowledge relying on dubious testimony to win convictions. Defendants serve mandatory minimum penalties for minimal offenses.

Constitutional interpretation is malformed. In Gonzales v. Raich the Supreme Court held that Uncle Sam could regulate someone who grew marijuana for personal consumption under the interstate Commerce Clause. Conservative jurist Antonin Scalia concurred in the opinion. His reasoning was used by the Left to argue that Obamacare was constitutional.

Federalism is another victim of the Drug War. Many conservatives complain about the over-criminalization of life, with a plethora of new federal offenses enforced by criminal penalties. In this way Washington is encroaching on an area traditionally a matter of state authority, along with such issues as education and welfare.

As some states decriminalized drug use and others allowed pot consumption for medical purposes, the federal government continued to prosecute all users and dealers. Someone could be dying and Uncle Sam would charge them with a criminal offense. Those involved with medical dispensaries remained vulnerable to federal charges and penalties.

The Tuesday election has provided another potential conflict. Citizens in Alaska and Oregon joined those in Colorado and Washington in legalizing marijuana. While the national government can continue separately prosecuting users, it can’t force states to toss people in jail for using drugs.

Washington, D.C. is different. District voters approved legalization by a more than two-to-one margin. Police Chief Cathy Lanier said she respected “the clear intent of District voters.”

However, since D.C. is under federal control, Congress can overturn District measures by passing a disapproval resolution within 60 days. Or legislators can apply annual riders blocking measures from taking effect, a Republican tactic used for 11 years straight against a medical marijuana initiative passed by D.C. in 1998.

Maryland Rep. Andy Harris is leading the latest charge, making the backward claim that legalization for adults would increase teen usage (actually, prohibition puts the trade in the hands of criminals who are only too happy to encourage kids to consume). He told the Washington Post: “I will consider using all resources available to a member of Congress to stop this action.” Earlier this year he won House approval for a legislative rider to block the D.C. city council’s vote to decriminalize marijuana, though the Senate refused to go along.

The GOP Senate takeover could give Harris a new opportunity. But Sen. Rand Paul (R‑KY) is set to take over the District oversight committee in that body and is skeptical of federal preemption. He said he hadn’t taken a stand on the D.C. measure, but added: “I’m against the federal government telling them they can’t.”

His position is the right one. Whatever one thinks of the substantive issue—I happen to favor legalization—Washington should not dictate policy to other levels of government. The fact that the District is a federal enclave doesn’t change the issue.

Congress can legitimately oversee a true federal zone. But most of the District is irrelevant to the national government’s operations. There’s a good argument for separating the inner core and returning the rest of the territory to Maryland. If not, however, residents should be allowed to manage their own affairs absent extraordinary circumstances. Which are not present in this case.

Beyond that, Congress may continue to impose national prohibition under its own authority. But it is highly intrusive, even dictatorial, for Uncle Sam to insist that a subordinate government criminalize a particular activity against the wishes of the majority of the latter’s people. Such a step also would encourage official deception: Congress can prevent the District from legalizing pot use, but in practice Congress cannot force the District to enforce prohibition. Overturning D.C.’s action would to turn the law into a polite lie.

Federalism long has been a position of convenience for most politicians. Few officials in Washington believe in any limits to their jurisdiction. They tend to recognize state authority only when doing so advances their substantive ends. Both Democrats and Republicans cheerfully abandon their professed principles when politically advantageous.

But the District’s vote on drugs gives the enhanced GOP House majority and new Republican Senate majority an opportunity to put principle before politics. Voters in the District of Columbia, no less than those in Alaska, Colorado, Oregon, and Washington, should be able to decide on their criminal laws. More than anyone else, conservatives should affirm this right (and responsibility). Let D.C. join the great laboratory of democracy known as the American states.